The European Space Agency has launched an initiative to develop complex metal 3D printing techniques for space missions. The Amaze initiative (standing for "Additive Manufacturing Aiming Towards Zero Waste and Efficient Production of High-Tech Metal Products", somehow) brings together 28 different organizations that have a stake in the process, either by research (Universities) or industry (AirBus, for example).
For ESA the results could be spectacular. By 3D printing an entire satellite in one single piece, they could significantly reduce the mission's weight. How? When multiple pieces are used, you must provide bolts and nuts to hold them together - plus reinforced holes to hold those bolts and nuts. All that adds up to a lot more weight - and size in some cases, too.
The benefit, they say, is a reduction in cost by half, and that's a big deal when your space expeditions cost millions.
The spin offs for the rest of us will be more efficient airplanes, reactors, vehicles.
And maybe a ticket to space we can actually afford.